Charge-coupled device (CCD) sensors and Complementary Metal-Oxide Semiconductor (CMOS) sensors are commonly used for imaging, of which the dynamic range is an important performance indicator. The dynamic range can be defined as the ratio of the highest illuminance to the lowest illuminance that an image sensor can measure with an acceptable output quality. HDR images usually appear crisper and richer than normal images, because of better retention of highlight and shadow details.
Some current technologies produce each HDR image by taking multiple shots of various exposure times and combining features from each shot. Such process may take a few seconds and is prone to motion artifacts caused by movements. Thus, it is desirable to improve the dynamic range and image quality through innovations in the sensor architecture.